This invention relates to a starter of internal combustion engines, and in particular a car's internal combustion engine starter with a disengaging pinion, electromagnetically disengaged to interact with the gear rim of the internal combustion engine.
Internal combustion engine starters are designed so that the disengaging pinion is disengaged to interact with the gear rim of the internal combustion engine through the action of a magnet core onto the pinion or frequently through a two-armed lever, and the magnet is situated outside the electric motor axis with the pinion so that their axes are parallel.
Another well known solution is when a disengaging magnet is situated on the pinion axis of the starter but the electric motor is situated in a position parallel thereto. In these starter embodiments the design of the electric motor includes an internal gearing with ferrite permanent magnets working at high speed and reducing the electric motor speed to the necessary pinion speed by the engagement of pinion teeth with gear rim teeth. This gearing is carried in the electric motor axis in the case of a planet solution, or in the pinion axis if this gearing is not situated on the electric motor axis.
U.S. Pat. No. 5,081,874 teaches a design solution for a starter, in which the pinion is engaged with a gear rim of an internal combustion engine through a transmission element formed by one disengaging bar inserted in an armature shaft cavity. This disengaging bar forms a dynamic unit with the mobile core of a disengaging electromagnet. If, upon pinion disengagement, the pinion teeth are striking the rim teeth of the internal combustion engine, the motion of the mobile core and the coupled disengaging bars will not stop, and a shooting spring inserted into the mobile core is compressed until the moment when the pinion tooth engages into the space of the gear rim tooth of the internal combustion engine. Because full current is already brought into the armature, and the pinion is rotating at its full output, the pinion will be intensively shot into the gear rim of the internal combustion engine, which is connected with spokes, and causing a great wear on the pinion teeth and gear rim teeth of the internal combustion engine. Another disadvantage of this U.S. patent is the necessity to secure the ball inserted between the pinion end and the engaging bar. This ball is inserted to inhibit the transmission of pinion rotative motion onto the mobile core upon spring compression, when a full output is already brought into the armature. Ball securement between the pinion end and the disengaging bar is very questionable, because the ball can easily drop out as a result of great dynamic strokes originating upon pinion engagement into the gear rim of the internal combustion engine.
A common disadvantage of these starter solutions is the wear on the pinion teeth and the flywheel gear rim teeth. Pinion teeth are inserted into the flywheel gear rim teeth. A shooting spring is applied at the striking of the pinion tooth into the flywheel gear rim tooth of the internal combustion engine. The shooting spring forcefully shoots the pinion at full torsional moment of the armature into the flywheel gear rim teeth.
Another disadvantage of all these above described solutions is complexity, and relative corresponding lower working reliability. Another disadvantage of all these solutions is the limited position of the assembly in the internal combustion engine. A disadvantage of starters with gears is also high noise upon starting due to its high speed function.